Steps:

1. Cut a 24-inch long section of the 2-by-4 to use as a reinforcement. Select a section of board that is free of knots. 2. Once cut, use a hand plane to shave the board down to 1-1/4-inch wide. Mark a line along the narrow edge using the combination square so you know how much material to remove. 3. Plane the 2-by-4 down to the desired thickness. 4. Hold the board in place next to the doorframe and mark the points where you'll drill. 5. Drill pilot holes though the board and into the 2-by-4 wall studs using the right-angle drill equipped with a countersinking bit. 6. Secure the piece to the wall studs using galvanized deck screws. 7. Switch to a wood-boring bit on your drill and drill a hole for the deadbolt. 8. Chisel out a deep enough area around the hole for your strike plate. Affix new door hardware.